Cluster bomb



Nov. 19, 1963 A, A. ALPERSTEIN 3,111,086

CLUSTER BOMB Filed April 2, 1955 INVENTOR. Fi 4 Abra/mm A/berf Alps/stem United States The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to me of any royalty thereon.

This invention relates to munitions and particularly to those which are dropped from a relatively high level to a target below, such as bombs dropped from aircraft or the like.

It is an object of this invention to provide a bomb of such configuration that it has good clusterability characteristics and maximum potential velocity for its weight. a It is another object of this invention to provide a clusterable bomb having maximum potential velocity for its weight, wherein its velocity, stability and penetration characteristics can be regulated by a simple alteration of the bomb.

It is a further object of the invention to provide a clusterable bomb having maximum potential velocity for its weight, which lends itself to easy manufacture by either casting or fabrication out of sheet metal.

It is a specific object of this invention to provide a clusterable bomb halving maximum potential velocity for its weight, wherein its configuration is determined by utilizing two mathematical equations.

It is a very specific object of this invention to provide a clusterable bomb having maximum potential velocity for its weight, which has no moving par-ts on the bomb body, such as movable fin structure or the like. This lack of movable parts increases the bombs ability to withstand extreme shock.

The above and other objects will become apparent from the following description taken in connection with the accompanying drawings wherein:

FIG. 1 is a side view of several of the improved bombs clustered together, some bombs being shown in elevation and others in section.

FIG. 2 is a diagrammatic view which aids in thee planation of how the configuration of the bombs is ascertained by utilizing two mathematical equations.

FIG. 3 is a side view in elevation of a portion of one of the bombs shown in FIG. 1 slightly altered.

' FIG. 4 is an end elevational view of a cluster bomb casing with portions of the casing broken away to show the cluster of bombs.

Incendiary bombs designed in accordance with my in vention are illustrated in clustered condition in FIG. 1. Bombs 1b and 1'2 are shown in elevation and bombs 14 and 16 are shown in section. All the bombs are identical, therefiore a detailed description of only one bomb will be made. Bomb 16 comprises steel nose section 18 and magnesium body and tail section 2%, which are secured to each other by a threaded joint formed by internally threaded flange portion 22 of the nose section and extemally threaded reduced portion 24 of the body and tail section.

Nose section .18 has an axial bore 26 formed therein that extends from the front of blunt nose end 27 rearwardly and communicates with smaller bore 28, which in turn communicates with enlarged bore 30. A plurality of passages 32 radiate from bore 3t? toward the surface of the nose section to a point where they communicate with enlarged recesses 34. A blowout plug 3-6 is positioned in each recess 34. A conventional percusssion cap 38 is positioned within bore 28 with its head facing atent amass the nose end of the bomb and opposing the-rearwardly facing pointed firing pin 4%, which is secured to firing. pin carrier 42. The firing pin carrier 42, its firing pin v charge 44 and conventional, incendiary charge 46. The

flared, tail portion 48 of body and tail section 20 has a forwardly extending axial recess 5t formed therein. From PEG. 1 it will be observed that the bombs are clustered tail to nose, and that when packed in this manner, adjacent bombs contact each other along their sides with little or no loss of space. It will also be observed that the forwardly projecting portion of the firing pin carrier of the bomb immediately to the rear fits within the recess in the tail of any given bomb. This can be clearly seen in FIG. 1, where it will be observed that the forward portion or" the firing pin carrier 42 of bomb l6 is received within the recess 52 in the tail of bomb 14.

The bombs shown in FIG. 1 are designated incendiary bombs and include the described structure for actuating the incendiary filling 46. In operation, upon striking a nesium body and tail section 2%. While the bombs illus-- trated in FIG. 1 are incendiary bombs, and the nose sec-' tion and the body and tail section are adapted to be molded, it should be understood that bombs with the same general configuration may also be employed withother fillings, such as a gas filling, and that in bombs of alternative types it is more expedient that the sections of the bomb be fabricated of sheet metal.

When the bombs are molded as those illustrated in FIG. 1, a single mold based on the designcan producebom-bs of various velocities, penetrating powers and degrees of stability. This may be accomplished by cutting out portions of the flared tail and thereby varying the.

drag. FIG. 3 shows incendiary bomb i FIG. 1 modified by having a portion of its tail cut out, thereby forming a wedge-shaped slot 54. The size, shape and depth of the slot formed by the cut out portions will determine; the amount that the velocity, stability and penetrating power is varied from that of the basic bomb,

A cluster of incendiary bombs of the type shown in- FIG. 1 are illustrated in FIG. 4 mounted in a cluster; bomb casing. The casing is conventional and comprises cylinder 56 having its ends closed. In FIG. 4, end closure 58, the only one shown, is broken away to show the clustered bombs. Cluster strap 60 and other straps (not shown) retain the clustered bombs as a unit prior to inserting the cluster in the casing 56. The casing and cluster straps per se form no part of my invention. FIG.

4 has been included solely to show the manner in which the bombs shown in FIG. 1 are clustered and mounted.

in a casing, for efiicient clusterability is one of the outstanding advantages of my improved bombs.

The shape of the bomb, which is critical, may be characterized as being fish-like when viewed from the side, such as in FIGS. 1 and 2, or as vase-shaped when set on its blunt nose end, such as by rotating FIG. 2

Patented Nov. 19, 1563.

a 90 counterclockwise. Each of these terms when used in the specification and claims is intended to include shapes such as those shown in the drawings, and other similar configurations, whether they have blunt or pointed noses. FIG. 2 illustrates graphically how the precise shape of the bombs shown in FIG. 1 is ascertained. it will be observed in FIG. 2 that a conventional x and y axis are prow'ded, and that the curve shown in solid lines running from point x to point x will generate the surface of a solid when revolved about the x axis. The portion of the curve from the nose of the bomb to the approximate maximum desired diameter of the bomb (from point x to point x is determined in accordance with the equation: y=Ax +B. The portion of the curve from the approximate maximum desired diameter of the bomb to the approximate minimum desired diameter (from point x to point x is determined by the equation:

The portion of the curve from the approximate minimum desired diameter of the bomb to the tail of the bomb (from point x to point x is determined by the inverse of the equation: y=Ax +B. In the two equations employed, the value of each of the constants A, B, C, D and E depends upon the overall, desired dimensions of the bomb.

The manner of designing a specific bomb by employing the two equations is as follows: the maximum desired diameter, the minimum desired diameter, the desired diameter of the blunt nose and the overall length of the bomb are initially assigned in accordance with the type of filling to be put in the bomb, the size of the cluster casing and other functional considerations. From these fixed values, a value for each of the constants may be ascertained. By referring to FIG. 2 it will be seen that the constant B equals one-half of the diameter of the blunt nose. The constant A equals the difference between one-half of the maximum desired diameter of the bomb and B. Since the diameter of the blunt nose and the maximum diameter of the bomb are both known, the numerical values for A and B may be ascertained. The constants 'C plus D equal one-half the maximum diameter of the bomb, and the constants C minus D equal one-half of the minimum diameter of the bomb. Since both the minimum and maximum diameters of the bomb are known, it is a simple matter to ascertain the value of C, for it is equal to one-half the minimum diameter of the bomb ('CD) plus one-half the dili'erence of one-half of the minimum and one-half of the maximum diameters of the bomb. Expressing it alternatively, C equals one-half of the sum of one-half of the maximum and one-half of the minimum diameters. Having the numerical value for C, it is a simple matter to find the numerical value for D, for it equals one-half the maximum diameter minus C. The constant E is defined as the axial length of the bomb from the maximum desired diameter to the minimum desired diameter (point x to point x A numerical value for E is ascent-aimed by subtracting from the overall length of the bomb, twice the distance along the x axis from the nose of the bomb to the maximum desired diameter (point x to point x The distance from point x to point x is determined by actually plotting the equation:

until the curve reaches the point above the x axis equal to one-half the maximum diameter of the bomb. Having ascertained the numerical value for the constants it is a simple matter of inserting them in the equations and plotting the curve from point x to point x which is the full desired length of the bomb. Descriptively, the curve from x to x is a portion of a parabola and the curve from x to x is identical, except that it is inverted. The curve between x and x is a portion of a cosine wave, extending from a maximum at x to a minimum at x and symmetrical about its midpoint. At the points where the parabola and cosine curves join, i.e. points x and x both type curves are substantially tangent to a line parallel to the x axis. The curve as a whole is, therefore, a smooth compound curve which is symmetrical about the midpoint of the portion which is a cosine curve. Because of this symmetry, the bombs will nest when placed nose-to-tail, as shown in FIG. 1.

From the foregoing it will be apparent that bombs may be designed by employing the two equations cited, and that by varying the values of the constants, the precise size and shape of the bombs can be varied. For example, in the case of an incendiary bomb it might be desirable to have a long, thin bomb, whereas in the case of a chemical bomb it might be desirable to have a short, stubby bomb. Also the bombs may be blunt nosed or pointed as desired. These variations can be accomplished by varying the values of the constants in the equations. Thus, the cosine portion of the curve may be long and flat or short and steep and the same variations are possible in the parabolic pontions. Regardless of those variations, however, the bombs will retain their property of nesting, together with the smoothly curving surface which produces high aerodynamic efficiency.

The precise contribution which I have made to this art by virtue of this invention is that l have developed the two equations and the manner of employing them to design specific bombs. Advantages of bombs designed in this manner are: they may be varied to alter their aerodynamic characteristics, they have no moving parts on the bomb body, and they have a maximum potential velocity for their weight.

Having described my invention in great detail, it is not thereby intended to limit the invention to the precise structure described, for it is intended to include all changes that might be made by one skilled in the art which fall within the spirit of the invention and the scope of the appended claims.

I claim:

1. An incendiary bomb comprising a heavy steel nose portion and a hollow unitary body and tail portion formed of inflammable material said bomb having an outmost exterior surface which is a surface of revolution generated by the rotation about the bomb of a smooth curve about the axis of said bomb, said curve beginning at the nose of said bomb and increasing to a maximum measured from said axis, then decreasing to a minimum, then increasing again to the tail of said bomb, said tail portion having longitudinal notches therein to reduce drag, said curve being symmetrical about a point intermediate its ends whereby said bomb is adapted to nest in noseato-tail relationship with bombs of substantially identical structure, the nose and tail ends of said bombs being flat, an incendiary charge in said hollow unitary tail portion, a firing device for said incendiary charge projecting from the nose end of said bomb, and said bomb further comprising a recess in said tail end at least as large as the projecting portion of said firing device, whereby when said bomb is clustered with a plurality of substantially identical bombs, the fiat nose end of one bomb may lie against the fiat nose of an adjacent bomb with the firing device of one bomb within the tail recess of the other bomb.

2. An incendiary bomb as defined in claim 1 comprising an axial bore in said steel nose portion extending throughout the length of said nose portion, a percussion cap mounted in said bore intermediate its length, a firing pin carrier mounted in said bore and projecting from the nose of the bomb, a firing pin on said carrier in alignment with said percussion cap, a shear element normally holding said carrier in position, a booster charge in said hollow unitary body and tail member in direct communication with said bore, at least one radial passage communicating with said bore between said booster charge Jthe axis of the bomb, said curve beginning at the nose of the bomb and increasing to a maximum measured from said axis, then decreasing to a minimum, then increasing again to the tail of said bomb, the nose and tail ends of each bomb being fiat, a firing device projecting axially from the nose of each bomb, an axial recess in the 'tailof each bomb, said recess being at least as large as the projecting portion of said firing device, said bombs being nested, laterally adjacent bombs being pointed in opposite direct-ions with the portion of maximum diameter of one bomb lying against the portion of diameter of an adjacent bomb, whereby, by reason of the symmetry of said curve, said bombs are in contact throughout their length, said bombs being axially aligned in rows with adjacent bombs being pointed in the same direction with the flat nose portion of a bomb against 2 the flat tail portion of the next bomb, the firing device 6 of each bomb lying within the tail recess of the next bomb, and a cluster easing surrounding said :bombs and holding them in position. 7

References Cited in the file of this patent UNITED STATES PATENTS 157,049 Wiard Nov. 17, 1874 279,964 Melford June 26, 1883 762,084 Peterson "June 7, 1904 1,003,082 Ziegenfuss Sept. 12,1911 1,194,363 Casanovas et al. Aug. 15, 1916 1,326,258 Graumann Dec. 30, 1919 1 1,357,927 Clarke Nov. 2, 1,794,141 Jorgensen Feb. 24, 1931 2,329,522 Duncan Sept. 14, 1943 2,358,792 Conway Sept. 26, 1944 2,379,383 Steel June 26, 1945 2,445,311 Cooke et a1 -1 July 20, 1948 2,447,036 Short -Aug. 17, 1948 2,476,973 Gillon July 26, 1949 2,604,043 Frisch et a1 July 22, 1952 FOREIGN PATENTS 31,912 Switzerland Nov. 17, 1904 506,115 Great'Britain May 23, 1939 866,269 France Apr. 21, 1941 

1. AN INCENDIARY BOMB COMPRISING A HEAVY STEEL NOSE PORTION AND A HOLLOW UNITARY BODY AND TAIL PORTION FORMED OF INFLAMMABLE MATERIAL SAID BOMB HAVING AN OUTMOST EXTERIOR SURFACE WHICH IS A SURFACE OF REVOLUTION GENERATED BY THE ROTATION ABOUT THE BOMB OF A SMOOTH CURVE ABOUT THE AXIS OF SAID BOMB, SAID CURVE BEGINNING AT THE NOSE OF SAID BOMB AND INCREASING TO A MAXIMUM MEASURED FROM SAID AXIS, THEN DECREASING TO A MINIMUM, THEN INCREASING AGAIN TO THE TAIL OF SAID BOMB, SAID TAIL PORTION HAVING LONGITUDINAL NOTCHES THEREIN TO REDUCE DRAG, SAID CURVE BEING SYMMETRICAL ABOUT A POINT INTERMEDIATE ITS ENDS WHEREBY SAID BOMB IS ADAPTED TO NEST IN NOSE-TO-TAIL RELATIONSHIP WITH BOMBS OF SUBSTANTIALLY IDENTICAL STRUCTURE, THE NOSE AND TAIL ENDS OF SAID BOMBS BEING FLAT, AN INCENDIARY CHARGE IN SAID HOLDIARY CHARGE PROJECTING FROM THE NOSE END OF SAID BOMB, AND SAID BOMB FURTHER COMPRISING A RECESS IN SAID TAIL END AT LEAST AS LARGE AS THE PROJECTING PORTION OF SAID FIRING DEVICE, WHEREBY WHEN SAID BOMB IS CLUSTERED WITH A PLURALITY OF SUBSTANTIALLY IDENTICAL BOMBS, THE FLAT NOSE END OF ONE BOMB MAY LIE AGAINST THE FLAT NOSE OF AN ADJACENT BOMB WITH THE FIRING DEVICE OF ONE BOMB WITHIN THE TAIL RECESS OF THE OTHER BOMB. 